This continuation of an established program emphasizes the techniques and concepts of cellular and molecular biology, genetics and chemistry applied to fundamental studies of immunology and bone biology in rheumatic and autoimmune diseases. The faculty are highly competent in research and training in: the immune response in mice and humans involving T cells, B cells, dendritic cells, eosinophils and mast cells including: regulation of their cytokines, genetic programs, gene rearrangement mechanisms, antigen presentation, T cell receptor recognition, adhesion and homing, cell biology, inhibitory and activating receptors, factors influencing autoantibody production, and lipid inflammatory mediators. Studies on bone and cartilage include: proteoglycans, the adverse effects of inflammatory processes on the skeletal bone of joints and mechanisms of osteoclast-mediated bone resorption, collagen structure, gene therapy and tissue engineering. Human and animal (mouse) studies of arthritis, synoviocytes and synovial biology and various autoimmune disease models in mice including gene therapy for arthritis, the development of the rheumatoid pannus, the role of leukocyte subsets, cytokines, adhesion molecules and inflammatory mediators in arthritis are studied. Other research in humans includes the epidemiology and risk factors involved in the development and outcomes of rheumatic diseases and their therapeutics and management. While the primary strength of the program resides in the direct and individual nature of the interaction in the laboratory between each fellow and the responsible faculty member(s), substantial didactic experiences and the medical school environment supplement training. Support is requested for 6 postdoctoral trainees having either an M.D., or Ph.D., or both, as well as for 1 predoctoral (Ph.D candidate) trainee.